IIvan Dědek et al., from CATRIN, Palacky University Olomouc, Czech Republic, published an article titled “High-Performance Carbon-Based Supercapacitors” in IOP Publishing Ltd. The team from CATRIN developed the SC-GN3 graphene material commercialized by Atomiver start up under an exclusive license from the university.
The article delves into the rapidly evolving landscape of carbon-based supercapacitors (SCs), particularly focusing on electric double-layer capacitors (EDLCs). These devices excel in fast charging, long cycle life, and high power density, making them suitable for a diverse range of applications, from consumer electronics to aerospace.
The discussion centers on advancements in activated carbon (AC), graphene, and their derivatives. However, it also acknowledges the challenges associated with transitioning high-performance materials from laboratory research to scalable commercial devices. Sustainability and systems-level optimization are recurring themes throughout the article.
Key Points:
- Carbon-based SCs have the potential to bridge the gap between traditional capacitors and lithium-ion batteries.
- Activated carbon and graphene are pivotal electrode materials, but real-world performance often falls short of laboratory results.
- Device architecture, electrode thickness, and testing methods significantly impact the performance outcomes of SCs.
- Emerging materials like N-doped graphene and graphdiyne offer promising potential but face scalability challenges.
- Electrolyte selection and thermal operating range are crucial for optimizing energy and power density in SCs.
- Environmental and safety standards must be met for industrial adoption of SCs.
In summary, the article begins by emphasizing the significance of supercapacitors in meeting the UN’s energy goals through improved electrochemical energy storage. EDLCs, in particular, offer advantages such as fast charge/discharge cycles, long life, and reduced safety risks. Carbon-based materials, particularly AC and graphene, dominate current SC technology due to their exceptional conductivity and abundance.
Real-world Supercapacitor (SC) performance often falls short of lab benchmarks due to variations in electrode thickness, device design, and performance reporting standards. Thin lab-scale electrodes perform better because they allow full ion accessibility, while practical devices with thicker electrodes exhibit lower capacitance. Additionally, volumetric energy densities tend to be diluted due to excessive porosity and low packing density of nanomaterials like graphene.
The paper delves into various carbon materials used for electrodes. Activated carbon, derived from biomass or plastic waste, is porous and cost-effective but hydrophobic. Surface functionalization or N-doping enhances ion accessibility and introduces pseudocapacitive effects. Graphene, although promising, faces restacking issues that reduce its surface area. Curved or defective graphene mitigates these limitations and has already demonstrated scalability in commercial devices. Graphdiyne, a newer carbon allotrope, holds great potential but faces challenges in production and consistency.
Device form factor significantly impacts SC performance. Wound-cell configurations offer scalability in manufacturing, while pouch-type cells are ideal for space-constrained designs. Each architecture comes with trade-offs in energy density, mechanical stability, and cost. The market demands SCs with higher energy densities, thermal stability, and compatibility with surface-mount technology, particularly for high-temperature reflow soldering.
Electrolytes play a pivotal role in determining SC performance. Aqueous electrolytes have voltage limitations, while organic electrolytes and ionic liquids offer wider voltage windows and improved energy density. However, ionic liquids are expensive and often viscous, hindering ion transport. Strategies such as blending ILs with low-viscosity solvents or developing eutectic mixtures are being explored to extend operational temperature ranges.
Manufacturing processes play a crucial role in the development of carbon-based supercapacitors (SCs). While NMP is commonly used as a solvent, it poses environmental risks, prompting research into safer alternatives such as water-based or green organic solvents. However, performance trade-offs remain a challenge.
The paper concludes with a call for holistic optimization. Improvements should target not only active materials but also electrolytes, device architecture, and regulatory alignment. Emerging directions include micro-supercapacitors and hybrid devices combining SCs and batteries. Continued interdisciplinary research is necessary to bridge the performance gap and make carbon-based SCs viable for widespread adoption.
In conclusion, carbon-based supercapacitors hold great promise for energy storage solutions that require rapid charge-discharge cycles, safety, and sustainability. While advanced materials like curved graphene and graphdiyne offer excellent electrochemical properties, industrial implementation is hindered by scalability, cost, and integration challenges. Addressing these challenges requires a systems-level approach, encompassing material innovation, manufacturing processes, and regulatory compliance. The future of SCs lies in their adaptability across diverse applications, and with ongoing research, they are poised to become indispensable components of next-generation energy systems.
Read the complete article here:
High-Performance Carbon-Based Supercapacitors, Ivan Dědek, Veronika Šedajová, Vojtěch Kupka, Tomáš Zedníček, Luca Primavesi, Doron Aurbach, Malachi Noked and Michal Otyepka, Accepted Manuscript. Published by IOP Publishing Ltd, DOI 10.1088/2053-1583/adf653, https://iopscience.iop.org/article/10.1088/2053-1583/adf653
